Fetch Data through Caml Query using textboxes as parameters

Hi All,

       *I am very new to SharePoint and working on SharePoint dev.I have task to get the list items based on 2 conditions and I am passing parameters as texboxes to get the data dynamically .

     *I had written the below code(Code 1) for which it is showing me errors and Code2 is working fine.Can any one help me what is error

Code 1

  SPList mylist = myweb.Lists["Manager"];
                SPItem myitem = mylist.Items.Add();
                SPQuery myquery = new SPQuery();
                string idvalue = txtid.Text.ToString();
                //myquery.Query = @"<Where><Eq><FieldRef Name='ID'/><Value Type='Number'>"+txtid.Text.ToString()+"</Value> </Eq></Where>";
                string idvaluuue=txtid.Text.ToString();;
                myquery.Query = @"<Where>
              <And>
                  <Eq>
                     <FieldRef Name='ID'/>
                     <Value Type='Number'>"+idvaluue+"</Value>
                  </Eq>
                   <Eq>
                     <FieldRef Name='NumberOfEvents'/>
                     <Value Type='Text'>"+drbcalenders.SelectedItem.Text.ToString()+"</Value>
                   </Eq>
               </And>
              </Where>";

Code 2

SPList mylist = myweb.Lists["sample"];
                SPItem myitem = mylist.Items.Add();
                SPQuery myquery = new SPQuery();
                string idvalue = txtid.Text.ToString();
                //myquery.Query = @"<Where><Eq><FieldRef Name='ID'/><Value Type='Number'>"+txtid.Text.ToString()+"</Value> </Eq></Where>";
                string idvaluuue=txtid.Text.ToString();;
                myquery.Query = @"<Where>
              <And>
                  <Eq>
                     <FieldRef Name='ID'/>
                     <Value Type='Number'>9</Value>
                  </Eq>
                   <Eq>
                     <FieldRef Name='NumberOfEvents'/>
                     <Value Type='Text'>July</Value>
                   </Eq>
               </And>
              </Where>";

Samar